N= []
N= int(input(" "))
 
if N>=30:
    print("Yes")
else:
    print("No") N= [] N [] N= int(input(" ")) N int(input(" ")) int input(" ") input " " if N>=30:
    print("Yes")
else:
    print("No") N>=30 N 30 print("Yes") print "Yes" print("No") print "No" N= int(input(" ")) int(input(" ")) N N= [] [] N
N= []
N= int(input(" "))
 
if N>=30:
    print("Yes")
else:
    print("No")